文献类型： 外文期刊

作者： Li, Xiaowei ¹ ; Zhang, Chenlu ¹ ; Zhang, Beibei ¹ ; Jiang, Li ¹ ; Tang, Shengqi ¹ ; Sun, Chenhui ¹ ; Bai, Yulong ¹ ; Wang, Yubang ¹ ; Shi, Yifei ¹ ; Ma, Lei ¹ ; Zhang, Wei ⁴ ; Ye, Qing ⁴ ; Yan, Junhua ⁴ ; Wang, Keya ⁴ ; Fu, Juemin ⁷ ; Du, Wenzhi ⁷ ; Ha, Denglong ¹ ; Ju, Yuxi ¹ ; Wan, Shiqiang ⁸ ; Hong, Liang ⁹ ; Fang, Yunting ¹⁰ ; Siemann, Evan ¹¹ ; Luo, Yiqi ¹² ; Reich, Peter B. ¹³ ; Ort, Donald ¹ ;

作者机构： 1.Henan Univ, Coll Geog Sci, Fac Geog Sci & Engn, Zhengzhou 450046, Henan, Peoples R China

2.Henan Univ, Res Stn Forest Ecosyst, Henan Dabieshan Natl Field Observat, Zhengzhou 450046, Henan, Peoples R China

3.Henan Univ, Key Lab Geospatial Technol Middle & Lower Yellow R, Minist Educ, Zhengzhou 450046, Henan, Peoples R China

4.Henan Univ, Coll Resources & Environm, Zhengzhou 450046, Henan, Peoples R China

5.Inst Cotton Res, Chinese Acad Agr Sci, State Key Lab Cotton Biol, Anyang 455000, Hebei, Peoples R China

6.Chinese Acad Sci, Key Lab Vegetat Restorat & Management Degraded Eco, South China Bot Garden, Guangzhou 510650, Guangdong, Peoples R China

7.Jigongshan Natl Nat Reserve, Xinyang 464039, Henan, Peoples R China

8.Hebei Univ, Inst Life Sci & Green Dev, Coll Life Sci, Hebei Basic Sci Ctr Biot Interact, Baoding 071002, Hebei, Peoples R China

9.Xinyang Normal Univ, Sch Math & Stat, Xinyang 464000, Henan, Peoples R China

10.Inst Appl Ecol, Chinese Acad Sci, CAS Key Lab Forest Ecol & Management, Shenyang 110016, Liaoning, Peoples R China

11.Rice Univ, Biosci Dept, Houston, TX 77025 USA

12.Cornell Univ, Coll Agr & Life Sci, Sch Integrat Plant Sci, Ithaca, NY 14850 USA

13.Univ Minnesota, Dept Forest Resources, St Paul, MN 55108 USA

14.Univ Michigan, Inst Global Change Biol, Ann Arbor, MI 48109 USA

15.Univ Michigan, Sch Environm & Sustainabil, Ann Arbor, MI 48109 USA

关键词： nitrogen deposition; forest canopy; carbon sequestration; 15 N recovery

期刊名称：PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA （ 影响因子：9.1； 五年影响因子：10.6 ）

ISSN： 0027-8424

年卷期： 2025 年 122 卷 34 期

页码：

收录情况： SCI

摘要： Atmospheric nitrogen (N) deposition is generally expected to stimulate plant carbon (C) sequestration and promote tree growth, thereby mitigating atmospheric CO2 accumulation. Yet, the magnitude of N deposition contribution to forest productivity remains contentious. While correlative studies suggest substantial plant growth enhancement, controlled fertilization experiments typically demonstrate a limited impact. This discrepancy may arise from whether or not to consider canopy N uptake processes. Here, we conducted a 10-y field experiment comparing canopy addition of N (CAN) with understory addition of N (UAN) at the rate of 0, 25, and 50 kg N ha(-1) y(-1) in a temperate deciduous forest in central China. We show that CAN significantly enhanced net primary productivity by 37.0% over control, driven by enhanced leaf litterfall, wood and fine root production, whereas UAN effects were marginal (8%). N-15 isotopic tracing revealed that CAN, through enhanced plant N uptake and increased ecosystem N retention, yielded a 3.5-fold higher C sequestration efficiency (triangle C/triangle N) of 54.5 +/- 7.7 kg C kg(-1) N, than UAN (12.2 +/- 3.4 kg C kg(-1) N) resulted from greater N loss through leaching. Physiological measurements indicated CAN enhanced leaf photosynthetic rates, modified leaf morphology, and extended leaf lifespan via delayed senescence. These findings provide robust empirical evidence that canopy N uptake is crucial for maximizing N-induced forest productivity, thereby holding significant implications for refining global C models and urging modelers to incorporate canopy processes for more accurate projections of future C sinks and climate change mitigation strategies.